Various attempts have been made to optimize the cooling of various automobile parts. Some of the various devices developed have been designed to control the air flow throughout the engine compartment of the automobile such that the desired amount of heat is transferred away from the engine, transmission, and other components which generate heat, in order to maintain an optimal operating temperature. It is also desirable to bring the engine up to the normal operating temperature as soon as possible after engine start-up; when the engine is substantially the same temperature as the surrounding environment. During this initial start-up period, the engine is the least fuel efficient, especially if during start-up the temperature of the surrounding environment is very cold. The reduced fuel efficiency is why it is considered desirable to bring the engine up to the optimal operating temperature very quickly. Under these conditions, it is not desirable to remove heat away from the engine and the various components surrounding the engine, and therefore, devices designed to control the air flow around the engine are more beneficially used if they do not remove a heat away from the engine at start-up.
Active grille systems have been developed which implement a frame having movable vanes capable of rotating between an open position and a closed position in order to selectively block or allow air flow into an engine compartment. During engine start-up the vanes can be closed in order to prevent outside air from flowing into the engine compartment and cooling the components of the engine, at least until the engine has reached optimal operating temperatures. Then once the desired engine temperature has been reached, the vanes can be opened or adjusted to allow air to flow through the engine compartment and cool the engine in order to help prevent the engine from becoming too hot.
The development and use of active grille systems presents a problem of how to control air flow through the vehicle compartment in the event of an electrical or actuator failure to the components of the active grille system, which will then result in lost ability to control the position of the vanes. If power or actuator failure occurs and the vanes are in the closed position, the engine compartment will not receive adequate air flow and the engine can overheat. It is therefore desirable to develop a fail-safe arrangement or actuator that will move the vanes to their open position in the event of power loss or actuator failure of the primary electrically driven active grille system actuator. It is further desirable to develop a fail safe module that has its own power source, independent from the rest of the vehicle and other active grille components.